<!DOCTYPE html>
<html>
<head>
<style>
body {
    _background: url(about:blank) fixed;
}
.fixable {
    position:fixed;
    top:100px;
    _position:absolute;
    _top:expression((document).documentElement.scrollTop+100);
}
</style>
</head>
<body style="height:1500px;">
<div class="fixable">fixable</div>
</body>
</html>